1. Field of the Invention
This invention relates to a device for changing the time flow rate of a liquid damping medium in a torsional oscillation or vibration damper, especially for piston engines, in whose rotating cylindrical damper housing, connected to the drive shaft and power takeoff shaft, pinions are mounted in planetary fashion and are engaged with a central gear seated on the power takeoff shaft or drive shaft, and form a gear pump for closed circulation of the damping medium, with a storage chamber with flexibly changeable volume, for example, a diaphragm reservoir or the like and/or a speed-controlled plunger valve being provided, whose piston is suitable for changing the cross section of the feed pipe as a throttle regulator by its axial motion.
2. Brief Description of the Prior Art
A device of this type is disclosed by DE-C-37 26 926, which corresponds to U.S. Pat. No. 4,905,807. Difficulties with internal leaks, especially with the gear pump, can also occur with this device, since it is possible because of internal leaks that may arise due to unwanted relative torsion forces. To avoid this, as with all other known torsional vibration oscillation dampers, relatively high-viscosity oils have to be used here as the damping medium. However, viscous oils have relatively poor lubricating properties, and are therefore rather undesirable in and of themselves.